U.S. patent application number 15/671394 was filed with the patent office on 2018-03-01 for substrate processing method.
The applicant listed for this patent is SCREEN Holdings Co., Ltd.. Invention is credited to Sadamu FUJII, Taiki HINODE, Rei TAKEAKI.
Application Number | 20180061677 15/671394 |
Document ID | / |
Family ID | 61243357 |
Filed Date | 2018-03-01 |
United States Patent
Application |
20180061677 |
Kind Code |
A1 |
HINODE; Taiki ; et
al. |
March 1, 2018 |
SUBSTRATE PROCESSING METHOD
Abstract
A substrate processing method includes a liquid film forming
step of supplying a low surface tension liquid onto the upper
surface of the substrate while rotating the substrate at a first
rotational speed, in order to form a liquid film of the low surface
tension liquid on the upper surface of the substrate, a rotation
decelerating step of decelerating rotation of the substrate to a
second rotational speed while continuing the liquid film forming
step, after a processing liquid on the substrate has been replaced
with the low surface tension liquid, an opening forming step of
forming an opening in the center region of the liquid film on the
substrate that rotates at the second rotational speed after
completion of the liquid film forming step, and a liquid film
removing step of removing the liquid film from the upper surface of
the substrate by widening the opening.
Inventors: |
HINODE; Taiki; (Kyoto,
JP) ; FUJII; Sadamu; (Kyoto, JP) ; TAKEAKI;
Rei; (Kyoto, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCREEN Holdings Co., Ltd. |
Kyoto |
|
JP |
|
|
Family ID: |
61243357 |
Appl. No.: |
15/671394 |
Filed: |
August 8, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/6719 20130101;
H01L 21/67028 20130101; H01L 21/02041 20130101; H01L 21/67034
20130101; H01L 21/6715 20130101; H01L 21/67051 20130101 |
International
Class: |
H01L 21/67 20060101
H01L021/67; H01L 21/02 20060101 H01L021/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2016 |
JP |
2016-168283 |
Claims
1. A substrate processing method comprising: a substrate holding
step of holding a substrate horizontally; a processing liquid
supply step of supplying a processing liquid containing a water,
onto the horizontally held substrate; a substrate rotating step of
rotating the horizontally held substrate; a liquid film forming
step of supplying a low surface tension liquid having lower surface
tension than water onto an upper surface of the horizontally held
substrate while rotating the substrate at a first rotational speed,
in order to replace the processing liquid on the substrate with the
low surface tension liquid and form a liquid film of the low
surface tension liquid on the upper surface of the substrate; a
rotation decelerating step of decelerating rotation of the
horizontally held substrate to a second rotational speed that is a
lower speed than the first rotational speed while continuing the
liquid film forming step, after the processing liquid on the
substrate has been replaced with the low surface tension liquid
having lower surface tension than water; an opening forming step of
forming an opening in a center region of the liquid film on the
substrate that rotates at the second rotational speed after
completion of the liquid film forming step; and a liquid film
removing step of removing the liquid film from the upper surface of
the substrate by widening the opening.
2. The substrate processing method according to claim 1, wherein
the first rotational speed is a speed at which the processing
liquid is spun off outward from the horizontally held
substrate.
3. The substrate processing method according to claim 1, wherein
the second rotational speed is a speed at which the liquid film is
held on the substrate.
4. The substrate processing method according to claim 1, wherein
the substrate rotating step includes a step of rotating the
substrate at a first processing liquid speed while supplying a
processing liquid containing a water, to the upper surface of the
horizontally held substrate; and the method further comprises a
substrate accelerating step of accelerating rotation of the
substrate that rotates at the first processing liquid speed to a
second processing liquid speed that is a higher speed than the
first processing liquid speed.
5. The substrate processing method according to claim 4, wherein
the second processing liquid speed is the same speed as the first
rotational speed.
6. The substrate processing method according to claim 1, further
comprising a substrate heating step of heating a substrate in a
state of holding the liquid film on the upper surface; wherein the
substrate heating step includes a heating interrupting step of
interrupting heating of the horizontally held substrate while the
opening forming step is being carried out.
7. The substrate processing method according to claim 6, wherein
the substrate heating step includes a heating resuming step of
resuming heating of the horizontally held substrate after
completion of the opening forming step.
8. The substrate processing method according to claim 6, wherein
the substrate heating step is initiated after completion of the
rotation decelerating step.
9. The substrate processing method according to claim 1, wherein
the opening forming step includes an inert gas blowing step of
blowing an inert gas toward the center region of the liquid
film.
10. The substrate processing method according to claim 1, further
comprising a low surface tension liquid supply step of supplying a
low surface tension liquid having a lower surface tension than
water onto the upper surface of the horizontally held substrate at
a position further outward than the opening.
11. The substrate processing method according to claim 10, further
comprising a step of moving the position on the upper surface of
the horizontally held substrate, to which the low surface tension
liquid having a lower surface tension than water is supplied, so as
to follow widening of the opening.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a substrate processing
method by which a substrate is processed. Examples of substrates to
be processed include substrates such as semiconductor wafers,
substrates for liquid crystal displays, substrates for plasma
displays, substrates for FEDs (field emission displays), substrates
for optical disks, substrates for magnetic disks, substrates for
magneto-optical disks, substrates for photomasks, ceramic
substrates, substrates for solar cells, etc.
2. Description of the Related Art
[0002] In substrate processing with a single substrate processing
type substrate processing apparatus that processes substrates one
by one, a chemical liquid is supplied to a substantially
horizontally held substrate by a spin chuck, for example. A rinse
liquid is then supplied to the substrate. Thereby, the chemical
liquid on the substrate is replaced with the rinse liquid. A spin
drying step is then carried out to remove the rinse liquid on the
substrate.
[0003] As shown in FIG. 10, in a case where a fine pattern is
formed on the front surface of the substrate, the rinse liquid that
has entered the interior of the pattern cannot be removed in the
spin drying step. Thus, drying defects may be caused. A liquid
surface of the rinse liquid that has entered the interior of the
pattern (an interface between the air and the liquid) is formed in
the interior of the pattern. Therefore, surface tension acts on the
liquid at a position where the liquid surface and the pattern are
in contact. In a case where the surface tension is high, the
pattern is more likely to collapse. Water, a typical rinse liquid,
has high surface tension. Therefore, collapse of the pattern in the
spin drying step cannot be ignored.
[0004] Thus, in order to dry the upper surface of the substrate, it
can be considered that isopropyl alcohol (IPA), which is a low
surface tension liquid having lower surface tension than water, is
supplied to replace the water which has entered the interior of the
pattern with the IPA, and thereafter the IPA is removed.
[0005] In the substrate processing described in Japanese Patent
Application Publication No. 2010-177371, after a liquid film of
water has been formed on the substrate, the liquid film of water is
replaced by IPA. The liquid film is then formed in an annular shape
by forming a hole at the center section of the IPA liquid film by
blowing nitrogen gas. Furthermore, by increasing the inner diameter
of the annular liquid film by applying centrifugal force to the IPA
on the substrate by rotation of the substrate, the IPA liquid film
is pushed to the outside of the substrate. The IPA is thus removed
from the top of the substrate.
[0006] During the substrate processing, when the liquid film of
water is to be replaced by IPA, rotation of the substrate is
accelerated in a stepwise manner in the order of 10 rpm, 50 rpm, 75
rpm, 100 rpm, and 500 rpm, after which the rotational speed of the
substrate is kept at 500 rpm. In addition, when the IPA liquid film
is shaped to an annular form and the inner diameter of the liquid
film is increased, the rotational speed of the substrate is changed
to 700 rpm.
SUMMARY OF THE INVENTION
[0007] In the substrate processing described in Japanese Patent
Application Publication No. 2010-177371, rotation of the substrate
is accelerated in a stepwise manner when the liquid film of water
is replaced by IPA. Consequently, along time is required for
replacement of the liquid film of water by IPA, and productivity
may potentially be reduced. Rotation of the substrate is also
further accelerated when the IPA liquid film is extruded from above
the substrate. Consequently, the action of increased centrifugal
force may result in disruption of the IPA liquid film on the upper
surface of the substrate and partial residue of IPA droplets on the
upper surface of the substrate. Until the droplets finally
evaporate, the liquid surface of the IPA (which may include trace
amounts of moisture dissolved in the IPA) continues to exert
surface tension on the pattern. Collapse of the pattern may
potentially occur as a result.
[0008] It is therefore one object of the present invention to
provide a substrate processing method that can shorten the time
required for formation of a liquid film of a low surface tension
liquid, and can satisfactorily remove the liquid film.
[0009] The present invention provides a substrate processing method
including a substrate holding step of holding a substrate
horizontally, a processing liquid supply step of supplying a
processing liquid containing a water, onto the horizontally held
substrate, a substrate rotating step of rotating the horizontally
held substrate, a liquid film forming step of supplying a low
surface tension liquid having lower surface tension than water onto
the upper surface of the horizontally held substrate while rotating
the substrate at a first rotational speed, in order to replace the
processing liquid on the substrate with the low surface tension
liquid and form a liquid film of the low surface tension liquid on
the upper surface of the substrate, a rotation decelerating step of
decelerating rotation of the horizontally held substrate to a
second rotational speed that is a lower speed than the first
rotational speed while continuing the liquid film forming step,
after the processing liquid on the horizontally held substrate has
been replaced with the low surface tension liquid having lower
surface tension than water, an opening forming step of forming an
opening in the center region of the liquid film on the substrate
that rotates at the second rotational speed after completion of the
liquid film forming step, and a liquid film removing step of
removing the liquid film from the upper surface of the substrate by
widening the opening.
[0010] According to this method, in the liquid film forming step, a
low surface tension liquid having lower surface tension than water
is supplied to the substrate that is rotating at the first
rotational speed that is a relatively high speed. After the
processing liquid on the substrate has been replaced with the low
surface tension liquid, and while continuing the liquid film
forming step, rotation of the substrate is decelerated to the
second rotational speed that is a lower speed than the first
rotational speed. Consequently, since the centrifugal force acting
on the processing liquid is great in comparison to a substrate
processing in which rotation of the substrate is accelerated in a
stepwise manner when the processing liquid on the substrate is
replaced with the low surface tension liquid, the time required
until the processing liquid on the substrate is replaced with the
low surface tension liquid is shortened. Stated differently, the
time until formation of the liquid film of the low surface tension
liquid is shortened.
[0011] Incidentally, the centrifugal force acting on the low
surface tension liquid on the substrate that rotates at the first
rotational speed is as great as the centrifugal force acting on the
processing liquid on the substrate. However, the low surface
tension liquid continues to be supplied onto the upper surface of
the substrate when the processing liquid on the substrate is
replaced with the low surface tension liquid. Disruption of the
liquid film during formation can therefore be minimized.
[0012] Furthermore, after completion of the liquid film forming
step, the opening is formed in the center region of the liquid film
in a state where the rotational speed of the substrate is kept at
the second rotational speed. Thus, the centrifugal force acting on
the liquid film is lowered in comparison to substrate processing in
which rotation of the substrate is accelerated in the opening
forming step or liquid film removing step. Therefore, disruption of
the liquid film is minimized and the liquid film is satisfactorily
removed from the upper surface of the substrate.
[0013] As described above, the time required for formation of the
liquid film of the low surface tension liquid can be shortened and
the liquid film can be satisfactorily removed.
[0014] In a preferred embodiment of the present invention, the
first rotational speed is a speed at which the processing liquid is
spun off outward from the horizontally held substrate. According to
this method, the processing liquid is spun off outward from the
substrate, and therefore the processing liquid on the substrate is
rapidly replaced by the low surface tension liquid.
[0015] In a preferred embodiment of the present invention, the
second rotational speed is a speed at which the liquid film is held
on the substrate. According to this method, the liquid film is held
on the substrate, and therefore disruption of the liquid film is
minimized.
[0016] In a preferred embodiment of the present invention, the
substrate rotating step includes a step of rotating the substrate
at a first processing liquid speed while supplying the processing
liquid that contains the water, onto the upper surface of the
horizontally held substrate. The substrate processing method
further includes a substrate accelerating step of accelerating
rotation of the substrate that rotates at the first processing
liquid speed, to a second processing liquid speed that is a faster
speed than the first processing liquid speed.
[0017] According to this method, the substrate is rotated at the
first processing liquid speed while the processing liquid is
supplied to the upper surface of the substrate, after which
rotation of the substrate is accelerated to the second processing
liquid speed which is a higher speed than the first processing
liquid speed. Processing of the upper surface of the substrate by
the processing liquid is therefore carried out rapidly.
[0018] In a preferred embodiment of the present invention, the
second processing liquid speed is the same speed as the first
rotational speed. According to this method, the second processing
liquid speed is the same speed as the first rotational speed, and
therefore the processing liquid on the substrate is replaced with
the low surface tension liquid while keeping the rotational speed
of the substrate at a high speed. The time required to change the
rotational speed of the substrate is thus reduced. Consequently,
the processing liquid on the substrate is rapidly replaced by the
low surface tension liquid.
[0019] In a preferred embodiment of the present invention, the
substrate processing method further includes a substrate heating
step of heating the substrate in a state where the liquid film is
held on the upper surface. The substrate heating step also includes
a heating interrupting step of interrupting heating of the
horizontally held substrate while the opening forming step is
carried out.
[0020] According to this method, the substrate is heated while the
liquid film is held on the upper surface, and vaporization of the
low surface tension liquid in the liquid film is thereby
accelerated. On the other hand, in a state where the opening
forming step is carried out, heating of the substrate is
interrupted. Consequently, an opening is satisfactorily formed in
the center region of the liquid film and the low surface tension
liquid is moderately vaporized. The liquid film on the substrate is
therefore rapidly removed by centrifugal force of rotation of the
substrate, and vaporization of the low surface tension liquid by
heating of the substrate. The liquid film on the upper surface of
the substrate is satisfactorily removed as a result.
[0021] In a preferred embodiment of the present invention, the
substrate heating step includes a heating resuming step of resuming
heating of the horizontally held substrate, after completion of the
opening forming step.
[0022] According to this method, heating of the substrate is
resumed after completion of the opening forming step, and therefore
vaporization of the low surface tension liquid in the liquid film
is accelerated even further after completion of the opening forming
step. The liquid film on the upper surface of the substrate is even
more satisfactorily removed as a result.
[0023] In a preferred embodiment of the present invention, the
substrate heating step is initiated after completion of the
rotation decelerating step. According to this method, the substrate
heating step is initiated after completion of the rotation
decelerating step. That is, heating of the substrate is interrupted
while the substrate is rotated at a relatively high speed.
Consequently, the liquid film is rapidly formed, and exposure of
the upper surface of the substrate due to disappearance of the low
surface tension liquid from the substrate before the opening
forming step is minimized.
[0024] In a preferred embodiment of the present invention, the
opening forming step includes an inert gas blowing step of blowing
an inert gas toward the center region of the liquid film. According
to this method, by blowing of an inert gas, the opening is
instantaneously formed in the center region of the liquid film
without leaving droplets.
[0025] In a preferred embodiment of the present invention, the
substrate processing method further includes a low surface tension
liquid supply step of supplying a low surface tension liquid having
a lower surface tension than water onto the upper surface of the
horizontally held substrate at a position further outward than the
opening.
[0026] According to this method, the low surface tension liquid is
supplied onto the upper surface of the substrate at a position
further outward than the opening, and therefore disruption of the
liquid film caused by local vaporization of the low surface tension
liquid on the outer side of the opening is minimized.
[0027] In a preferred embodiment of the present invention, the
substrate processing method further includes a step of moving the
position on the upper surface of the horizontally held substrate,
to which the low surface tension liquid having a lower surface
tension than water is supplied, so as to follow widening of the
opening.
[0028] According to this method, by moving the position on the
upper surface of the substrate, to which the low surface tension
liquid is supplied, so as to follow widening of the opening, the
low surface tension liquid continues to be supplied to a position
further outward than the opening, regardless of the size of the
opening. Consequently, disruption of the liquid film caused by
local vaporization of the low surface tension liquid on the outer
side of the opening is further minimized.
[0029] The above and other elements, features, steps,
characteristics and advantages of the present invention will become
more apparent from the following detailed description of preferred
embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is an illustrative plan view for explaining a layout
of the interior of a substrate processing apparatus according to a
first preferred embodiment of the present invention.
[0031] FIG. 2 is an illustrative lateral cross-sectional view for
explaining a configuration example of a processing unit provided in
the substrate processing apparatus.
[0032] FIG. 3 corresponds to a vertically sectional view taken
along line in FIG. 2 and is a schematic view for explaining the
configuration example of the processing unit.
[0033] FIG. 4 is a block diagram for explaining an electrical
configuration of the main portion of the substrate processing
apparatus.
[0034] FIG. 5 is a flowchart for explaining an example of substrate
processing performed by the substrate processing apparatus.
[0035] FIG. 6 is a time chart for explaining the details of
substrate processing.
[0036] FIG. 7A to FIG. 7D are illustrative cross-sectional views
for explaining the details of organic solvent processing (S4 in
FIG. 5).
[0037] FIG. 8 is an illustrative cross-sectional view for
explaining a configuration example of a processing unit in a
substrate processing apparatus according to a second preferred
embodiment of the present invention.
[0038] FIG. 9 is an illustrative cross-sectional view for
explaining a configuration example of a processing unit in a
substrate processing apparatus according to a third preferred
embodiment of the present invention.
[0039] FIG. 10 is an illustrative sectional view for explaining
principles of pattern collapse due to surface tension.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Preferred Embodiment
[0040] FIG. 1 is an illustrative plan view for explaining a layout
of the interior of a substrate processing apparatus 1 according to
a first preferred embodiment of the present invention. The
substrate processing apparatus 1 is a single substrate processing
type apparatus that processes substrates W such as silicon wafers
one by one. In this preferred embodiment, each of the substrates W
is a circular substrate. A fine pattern is formed on the front
surface of the substrate W (refer to FIG. 10).
[0041] The substrate processing apparatus 1 includes a plurality of
processing units 2 that process the substrates W, a plurality of
load ports LP that respectively hold carriers C housing the
plurality of substrates W to be processed by the processing units
2, transfer robots IR and CR that transfer the substrates W between
the load ports LP and the processing units 2, and a controller 3
that controls the substrate processing apparatus 1. The transfer
robot IR transfers the substrates W between the carriers C and the
transfer robot CR. The transfer robot CR transfers the substrates W
between the transfer robot IR and the processing units 2. The
plurality of processing units 2 may have the same configuration,
for example.
[0042] FIG. 2 is an illustrative lateral cross-sectional view for
explaining a configuration example of the processing unit 2. FIG. 3
corresponds to a vertically sectional view taken along line in FIG.
2. FIG. 3 is a schematic view for explaining the configuration
example of the processing unit 2.
[0043] The processing unit 2 includes a spin chuck 5 that rotates a
single substrate W around a vertical rotational axis C1 running
through the center of the substrate W while holding the substrate W
in a horizontal orientation. The spin chuck 5 is an example of a
substrate holding unit that holds the substrate W horizontally. The
processing unit 2 further includes a shielding member 6 having a
facing surface 6a which faces the upper surface of the substrate W
(the main surface on the upper side), and a chamber 7 housing the
substrate W for processing the substrate W with the processing
liquid. The shielding member 6 is an example of a facing member. In
the chamber 7, a carry-in/carry-out port 7A for carrying in and
carrying out the substrate W is formed. The chamber 7 includes a
shutter unit 7B that opens and closes the carry-in/carry-out port
7A.
[0044] The spin chuck 5 includes chuck pins 20, a spin base 21, a
rotating shaft 22, and an electric motor 23 that rotates the
rotating shaft 22 around the rotational axis C1.
[0045] The rotating shaft 22 extends in the vertical direction
along the rotational axis C1 (also referred to as the vertical
direction Z). In this preferred embodiment, the rotating shaft 22
is a hollow shaft. The upper end of the rotating shaft 22 is
coupled to the center of the lower surface of the spin base 21. The
spin base 21 has a disk shape along the horizontal direction. The
plurality of chuck pins 20 that grip the substrate W are disposed
at intervals in the circumferential direction in the peripheral
edge portion of the upper surface of the spin base 21. By rotating
the rotating shaft 22 by the electric motor 23, the substrate W is
rotated around the rotational axis C1. Hereinafter, the inner side
in the rotation radial direction of the substrate W shall be
referred to simply as the "radially inner side," and the outer side
in the rotation radial direction of the substrate W shall be
referred to simply as the "radially outer side."
[0046] The shielding member 6 is formed as a disk shape having the
substantially same diameter as the substrate W or the larger
diameter than the substrate W. The shielding member 6 is disposed
substantially horizontally above the spin chuck 5. A hollow shaft
30 is fixed to the surface of the shielding member 6 on the
opposite side of the facing surface 6a. In the portion of the
shielding member 6 including a position overlapping with the
rotational axis C1 in plan view, a communicating hole 6b that runs
vertically through the shielding member 6 and communicates with the
interior space of the hollow shaft 30 is formed.
[0047] The processing unit 2 further includes a shielding member
support member 31, a shielding member raising/lowering mechanism
32, and a shielding member rotating mechanism 33. The shielding
member support member 31 extends horizontally and supports the
shielding member 6 via the hollow shaft 30. The shielding member
raising/lowering mechanism 32 is coupled to the shielding member 6
via the shielding member support member 31 and drives raising and
lowering of the shielding member 6. The shielding member rotating
mechanism 33 rotates the shielding member 6 around the rotational
axis C1.
[0048] The shielding member raising/lowering mechanism 32 can
position the shielding member 6 at any desired position (height)
from a lower position to a higher position. The lower position is a
position within the movable range of the shielding member 6, at
which the facing surface 6a of the shielding member 6 is the
closest to the substrate W. In a state where the shielding member 6
is positioned at the lower position, a distance between the upper
surface of the substrate W and the facing surface 6a is 0.5 mm, for
example. The higher position is a position within the movable range
of the shielding member 6, at which the facing surface 6a of the
shielding member 6 is the most distant from the substrate W. In a
state where the shielding member 6 is positioned at the higher
position, the distance between the upper surface of the substrate W
and the facing surface 6a is 80 mm, for example.
[0049] The shielding member rotating mechanism 33 includes an
electric motor built into the tip of the shielding member support
member 31. A plurality of wirings 34 disposed inside the shielding
member support member 31 are connected to the electric motor. The
plurality of wirings 34 include a power line for power transmission
to the electric motor, and an encoder line for output of rotational
information of the shielding member 6. By detecting the rotational
information of the shielding member 6, rotation of the shielding
member 6 can be accurately controlled.
[0050] The processing unit 2 further includes an exhaust bucket 40
that surrounds the spin chuck 5, a plurality of cups 41, 42 (a
first cup 41 and a second cup 42) disposed between the spin chuck 5
and the exhaust bucket 40, and a plurality of guards 43 to 45 (a
first guard 43, a second guard 44, and a third guard 45) that
receive the processing liquid removed to a outside of the substrate
W from the substrate W held by the spin chuck 5.
[0051] The processing unit 2 further includes a plurality of guard
raising/lowering mechanisms 46 to 48 (a first guard
raising/lowering mechanisms 46, a second guard raising/lowering
mechanisms 47,and a third guard raising/lowering mechanisms 48)
that drive raising and lowering of the plurality of guards 43 to
45, respectively. In the present preferred embodiment, each pair of
the guard raising/lowering mechanisms 46 to 48 is provided in point
symmetry with respect to the rotational axis C1 of the substrate W
in plan view. Thereby, the plurality of guards 43 to 45 can be
respectively stably raised and lowered.
[0052] The exhaust bucket 40 includes a cylinder portion 40A of a
cylindrical shape, a plurality of (two, in the present preferred
embodiment) projecting portions 40B projecting from the cylinder
portion 40A to the radially outer side of the cylinder portion 40A,
and a plurality of lid portions 40C attached to the upper ends of
the plurality of projecting portions 40B. The plurality of guard
raising/lowering mechanisms 46 to 48 are disposed at the same
positions as the projecting portions 40B in the circumferential
direction of the cylinder portion 40A, further to the radially
inner side than the projecting portions 40B. In detail, one set of
the first guard raising/lowering mechanism 46, the second guard
raising/lowering mechanism 47, and the third guard raising/lowering
mechanism 48 is disposed at the same position as each of the
projecting portions 40B in the circumferential direction of the
cylinder portion 40A.
[0053] Each of the cups 41, 42 has an annular groove opening
upward. Each of the cups 41, 42 surrounds the spin chuck 5 further
to the radially inner side than the cylinder portion 40A of the
exhaust bucket 40. The second cup 42 is disposed further to the
radially outer side than the first cup 41. The second cup 42 is
integrated with the third guard 45, for example. The second cup 42
is raised and lowered together with the third guard 45. A waste
liquid piping (not shown) or a discharge piping (not shown) is
connected to the groove of each of the cups 41, 42. The processing
liquid guided to a bottom portion of each of the cups 41, 42 is
recovered or discarded through the waste liquid piping or the
discharge piping.
[0054] The guards 43 to 45 are disposed so as to surround the spin
chuck 5 and the shielding member 6 in plan view.
[0055] The first guard 43 includes a first cylindrical portion 43A
that surrounds the spin chuck 5 further to the radially inner side
than the cylinder portion 40A of the exhaust bucket 40, and a first
extension portion 43B extending to the radially inner side from the
first cylindrical portion 43A.
[0056] The first guard 43 is raised and lowered between a lower
position and a higher position by the first guard raising/lowering
mechanisms 46. When the first guard 43 is positioned at the lower
position, the upper end (the radially inner side end) of the first
guard 43 is positioned lower than the substrate W. When the first
guard 43 is positioned at the higher position, the upper end (the
radially inner side end) of the first guard 43 is positioned higher
than the substrate W. By being raised and lowered by the first
guard raising/lowering mechanisms 46, the first guard 43 can be
positioned at a shielding member facing position and a substrate
facing position between the lower position and the higher position.
When the first guard 43 is positioned at the substrate facing
position, (the radially inner side end of) the first extension
portion 43B faces the substrate W from the horizontal direction.
When the first guard 43 is positioned at the shielding member
facing position, (the radially inner side end of) the first
extension portion 43B faces the shielding member 6 from the
horizontal direction.
[0057] When the first guard 43 is positioned at the shielding
member, facing position, a space A where movement of the atmosphere
in from and out to the outside of the space A is restricted, is
formed by the first guard 43, together with the substrate W held on
the spin chuck 5 and the shielding member 6. The outside of the
space A is a space higher than the shielding member 6 and a space
further to the radially outer side than the first guard 43. The
space A only needs to be formed such that a flow of a fluid between
the atmosphere inside the space A and the atmosphere outside the
space A is restricted. The space A does not necessarily have to be
formed such that the atmosphere inside the space A is completely
shielded from the atmosphere outside the space A.
[0058] The second guard 44 includes a second cylindrical portion
44A that surrounds the spin chuck 5 further to the radially inner
side than the first cylindrical portion 43A of the first guard 43,
and a second extension portion 44B extending to the radially inner
side from the second cylindrical portion 44A.
[0059] The second guard 44 is raised and lowered between a lower
position and a higher position by the second guard raising/lowering
mechanisms 47. When the second guard 44 is positioned at the lower
position, the upper end (the radially inner side end) of the second
guard 44 is positioned lower than the substrate W. When the second
guard 44 is positioned at the higher position, the upper end (the
radially inner side end) of the second guard 44 is positioned
higher than the substrate W. By being raised and lowered by the
second guard raising/lowering mechanisms 47, the second guard 44
can be positioned at a substrate facing position between the lower
position and the higher position. When the second guard 44 is
positioned at the substrate facing position, (the radially inner
side end of) the second extension portion 44B faces the substrate W
from the horizontal direction. The second extension portion 44B
faces the first extension portion 43B from the lower side. When the
second guard 44 is positioned at the substrate facing position, the
space A is partitioned by the second guard 44 from the lower
side.
[0060] The third guard 45 includes a third cylindrical portion 45A
that surrounds the spin chuck 5 further to the radially inner side
of the second cylindrical portion 44A of the second guard 44, and a
third extension portion 45B extending to the radially inner side
from the third cylindrical portion 45A. The third extension portion
45B faces the second extension portion 44B from the lower side.
[0061] The third guard 45 is raised and lowered between a lower
position and a higher position by the third guard raising/lowering
mechanisms 48 (refer to FIG. 2). When the third guard 45 is
positioned at the lower position, the upper end (the radially inner
side end) of the third guard 45 is positioned lower than the
substrate W. When the third guard 45 is positioned at the higher
position, the third guard 45 is positioned higher than the
substrate W. By being raised and lowered by the third guard
raising/lowering mechanisms 48, the third guard 45 can be
positioned at a substrate facing position between the lower
position and the higher position. When the third guard 45 is
positioned at the substrate facing position, (the radially inner
side end of) the third extension portion 45B faces the substrate W
from the horizontal direction.
[0062] The processing unit 2 includes a lower surface nozzle 8 that
supplies a heating fluid to the lower surface of the substrate W,
and a chemical liquid nozzle 9 that supplies a chemical liquid such
as hydrofluoric acid to the upper surface of the substrate W.
[0063] The lower surface nozzle 8 is inserted through the rotating
shaft 22. The lower surface nozzle 8 has a discharge port facing
the center of the lower surface of the substrate W at the upper
end. A heating fluid such as hot water is supplied from a heating
fluid supply source to the lower surface nozzle 8 via a heating
fluid supply pipe 50. The heating fluid supply pipe 50 is provided
with a heating fluid valve 51 that opens and closes a flow passage
of the heating fluid supply pipe 50. Hot water is water at a higher
temperature than room temperature, such as 80.degree. C. to
85.degree. C. The heating fluid is not limited to hot water but may
be a gas such as a high-temperature nitrogen gas. In short, the
heating fluid may be a fluid that is capable of heating the
substrate W.
[0064] The chemical liquid is supplied from a chemical liquid
supply source to the chemical liquid nozzle 9 via a chemical liquid
supply pipe 53. A chemical liquid valve 54 that opens and closes a
flow passage of the chemical liquid supply pipe 53 is interposed in
the chemical liquid pipe 53.
[0065] The chemical liquid is not limited to hydrofluoric acid but
may be a liquid containing at least one of sulfuric acid, acetic
acid, nitric acid, hydrochloric acid, hydrofluoric acid, ammonia
water, hydrogen peroxide water, organic acids (such as citric acid,
oxalic acid, etc.), organic alkalis (such as TMAH:
tetramethylammonium hydroxide, etc.), surfactants, and corrosion
inhibitors. Examples of a chemical liquid containing mixture of
these include SPM (sulfuric acid/hydrogen peroxide mixture) and SC1
(ammonia-hydrogen peroxide mixture), etc.
[0066] The chemical liquid nozzle 9 is moved in the vertical
direction and the horizontal direction by a chemical liquid nozzle
moving mechanism 52 (refer to FIG. 2). The chemical liquid nozzle 9
is moved between a center position and a retreat position by
movement in the horizontal direction. When the chemical liquid
nozzle 9 is positioned at the center position, the chemical liquid
nozzle 9 faces a rotation center position of the upper surface of
the substrate W. When the chemical liquid nozzle 9 is positioned at
the retreat position, the chemical liquid nozzle 9 does not face
the upper surface of the substrate W. The rotation center position
of the upper surface of the substrate W is a position of the upper
surface of the substrate W, the position crossing the rotational
axis C1. The retreat position is a position on the outer side of
the spin base 21 in plan view.
[0067] The processing unit 2 further includes a DIW nozzle 10, a
central IPA nozzle 11, and an inert gas nozzle 12. The DIW nozzle
10 supplies deionized water (DIW) serving as a processing liquid to
a center region of the upper surface of the substrate W. The
central IPA nozzle 11 supplies IPA serving as a low surface tension
liquid having lower surface tension than water to the center region
of the upper surface of the substrate W. The inert gas nozzle 12
supplies an inert gas such as a nitrogen gas (N2) to the center
region of the upper surface of the substrate W. The center region
of the upper surface of the substrate W is a region around the
center of the upper surface of the substrate W. The center region
of the upper surface of the substrate W includes the position
crossing the rotational axis C1 on the upper surface of the
substrate W.
[0068] In this preferred embodiment, the nozzles 10 to 12 are
housed in common in a nozzle housing member 35 inserted through the
interior space of the hollow shaft 30 and the communicating hole 6b
of the shielding member 6. The nozzles 10 to 12 can discharge the
DIW, the IPA, and the inert gas, respectively. The tips of the
respective nozzles 10 to 12 are disposed at heights substantially
equal to the facing surface 6a of the shielding member 6. Even in a
state where the space A is formed, the respective nozzles 10 to 12
can supply the DIW, the IPA, and the inert gas, respectively, to
the center region of the upper surface of the substrate W.
[0069] The DIW is supplied from a DIW supply source to the DIW
nozzle 10 via a DIW supply pipe 55. A DIW valve 56 that opens and
closes a flow passage in the DIW supply pipe 55 is interposed in
the DIW supply pipe 55.
[0070] The DIW nozzle 10 may also be a processing liquid nozzle
that supplies a processing liquid other than the DIW. The DIW
nozzle 10 is an example of a processing liquid supply unit. The
processing liquid includes a rinse liquid. Examples of a rinse
liquid other than the DIW include carbonated water, electrolyzed
ion water, ozone water, aqueous hydrochloric acid solutions of
dilute concentration (of about 10 to 100 ppm, for example), and
reduced water (hydrogen water), etc.
[0071] The IPA is supplied from an IPA supply source to the central
IPA nozzle 11 via a central IPA supply pipe 57. A central IPA valve
58 that opens and closes a flow passage in the central IPA supply
pipe 57 is interposed in the central IPA supply pipe 57.
[0072] In the present preferred embodiment, the central IPA nozzle
11 is configured to supply the IPA. The central IPA nozzle 11 only
needs to function as a central low surface tension liquid nozzle
that supplies a low surface tension liquid with lower surface
tension than water to the center region of the upper surface of the
substrate W.
[0073] As the low surface tension liquid, an organic solvent other
than the IPA, which does not chemically react (or has low
reactivity) with the upper surface of the substrate W and the
pattern formed on the substrate W (refer to FIG. 10) can be used.
More specifically, a liquid including at least one of the IPA, HFE
(hydrofluoroether), methanol, ethanol, acetone, and
trans-1,2-dichloroethylene can be used as the low surface tension
liquid. In addition, the low surface tension liquid does not need
to be composed of a single component only, but may be a liquid
mixture with other components. For example, the low surface tension
liquid may be a mixture of an IPA solution and purified water, or a
mixture of an IPA solution and an HFE solution.
[0074] The inert gas such as the nitrogen gas is supplied from an
inert gas supply source to the inert gas nozzle 12 via a first
inert gas supply pipe 59. A first inert gas valve 60 that opens and
closes a flow passage of the first inert gas supply pipe 59 is
interposed in the first inert gas supply pipe 59. The inert gas is
a gas which is inert to the upper surface of the substrate W and
the pattern. The inert gas is not limited to the nitrogen gas but
may be a rare gas such as argon, for example.
[0075] By a space between an outer peripheral surface of the nozzle
housing member 35, and an inner peripheral surface of the hollow
shaft 30 and a surface partitioning the communicating hole 6b in
the shielding member 6, an inert gas flow channel 18 through which
the inert gas is supplied to the center region of the substrate W
is formed. The inert gas such as the nitrogen gas is supplied from
an inert gas supply source to the inert gas flow channel 18 via a
second inert gas supply pipe 67. The second inert gas supply pipe
67 is provided with a second inert gas valve 68 that opens and
closes a flow passage in the second inert gas supply pipe 67. The
inert gas supplied to the inert gas flow channel 18 is discharged
from the lower end of the communicating hole 6b toward the upper
surface of the substrate W.
[0076] The processing unit 2 may further include a moving nozzle 19
that supplies a chemical liquid, rinse liquid or a low surface
tension liquid to the upper surface of the substrate W (refer to
FIG. 2). The moving nozzle 19 is moved in the vertical direction
and the horizontal direction by a moving nozzle moving mechanism
19A (refer to FIG. 2).
[0077] The processing unit 2 further includes an IPA nozzle 13 that
supplies a low surface tension liquid such as IPA to the upper
surface of the substrate W.
[0078] The IPA nozzle 13 is an example of a low surface tension
liquid supply unit that supplies a low surface tension liquid to
the upper surface of the substrate W. The IPA nozzle 13 extends
from the inner wall of the first guard 43, so as to be disposed in
the space A in a state where the space A is formed.
[0079] The IPA is supplied from an IPA supply source to the IPA
nozzle 13 via an IPA supply pipe 61. An IPA valve 62 that opens and
closes a flow passage of the IPA supply pipe 61 is interposed in
the IPA supply pipe 61.
[0080] Referring to FIG. 2, the IPA nozzle 13 extends in the
horizontal direction and is curved in plan view. In detail, the IPA
nozzle 13 has an arc shape following the first cylindrical portion
43A of the first guard 43. A discharge port 13a that discharges the
IPA toward the upper surface of the substrate W in the vertical
direction (downward) is provided in the tip of the IPA nozzle
13.
[0081] Referring to FIG. 3, the processing unit 2 further includes
an IPA nozzle moving mechanism 16 coupled to the first guard 43,
that moves the IPA nozzle 13 in the horizontal direction between
the upper surface of the substrate W and the facing surface 6a of
the shielding member 6.
[0082] The IPA nozzle 13 is moved between a center position and a
retreat position by the IPA nozzle moving mechanism 16. When the
IPA nozzle 13 is positioned at the center position, the IPA nozzle
13 faces the rotation center position of the upper surface of the
substrate W. When the IPA nozzle 13 is positioned at the retreat
position, the IPA nozzle 13 does not face the upper surface of the
substrate W. The retreat position is a position on the outer side
than the spin base 21 in plan view. The retreat position of the IPA
nozzle 13 may be a position adjacent to the first cylindrical
portion 43A of the first guard 43 from the radially inner side.
[0083] The IPA nozzle moving mechanism 16 includes a support member
80 that supports the IPA nozzle 13, a driving mechanism 81 that is
coupled to the first guard 43 and drives the support member 80, and
a cover 82 that covers at least a portion of the driving mechanism
81. The support member 80 has the form of a rotating shaft that is
driven by the driving mechanism 81 to rotate around a prescribed
central axis.
[0084] The upper end of the support member 80 is positioned higher
than the cover 82. The IPA nozzle 13 and the support member 80 may
be formed integrally. The support member 80 and the IPA nozzle 13
have the form of hollow shafts. The interior space of the support
member 80 and the interior space of the IPA nozzle 13 communicate
with each other. The IPA supply pipe 61 is inserted through the
support member 80 from the upper side.
[0085] The first extension portion 43B of the first guard 43
integrally includes an inclined section 43C that is inclined with
respect to the horizontal direction, and a flat section 43D that is
flat in the horizontal direction. The flat section 43D and the
inclined section 43C are disposed side by side in the rotational
direction of the substrate W (refer to FIG. 2). The flat section
43D projects higher than the inclined section 43C such that the
flat section is positioned higher than the inclined section 43C as
the flat section 43D approaches the radially outer side. The flat
section 43D is disposed so as to overlap with the support member 80
and with the IPA nozzle 13 that is positioned on the outer side of
the spin base 21 in plan view. The flat section 43D only needs to
be disposed so as to overlap at least with the IPA nozzle 13 at the
retreat position and the support member 80 in plan view.
[0086] The second extension portion 44B of the second guard 44
faces the flat section 43D from the lower side. Between the first
guard 43 and the second guard 44, a housing space B where the IPA
nozzle 13 can be housed is formed. The housing space B extends in
the rotational direction of the substrate W following the first
cylindrical portion 43A of the first guard 43, and has an arc shape
in plan view. The housing space B is a space partitioned by the
first cylindrical portion 43A, the flat section 43D, and the second
extension portion 44B. In detail, the housing space B is
partitioned from the radially outer side by the first cylindrical
portion 43A, partitioned from the upper side by the flat section
43D, and partitioned from the lower side by the second extension
portion 44B. When the IPA nozzle 13 is positioned at the retreat
position, the IPA nozzle 13 is housed in the housing space B and is
close to the flat section 43D from the lower side. The second
extension portion 44B is inclined with respect to the horizontal
direction, so as to rise upward as the second extension portion 44B
goes toward the radially inner side. Thus, the housing space B is
maintained even when the second extension portion 44B is adjacent
to the first extension portion 43B from the lower side.
[0087] A penetrating hole 43E running through the flat section 43D
in the vertical direction Z is formed in the flat section 43D of
the first guard 43. The support member 80 is inserted through the
penetrating hole 43E. A sealing member made of rubber, etc., (not
shown) is disposed between the support member 80 and the inner wall
of the penetrating hole 43E. Thereby, a region between the support
member 80 and the inner wall of the penetrating hole 43E is sealed.
The driving mechanism 81 is disposed outside the space A.
[0088] The processing unit 2 further includes a first bracket 70, a
pedestal 71, and a second bracket 72. The first bracket 70 is
attached to the first guard raising/lowering mechanism 46 and fixes
the IPA nozzle moving mechanism 16 to the first guard 43. The
pedestal 71 is supported by the first bracket 70 and the driving
mechanism 81 is mounted on and fixed to the pedestal 71. The second
bracket 72 is coupled to the first guard 43 and supports the
pedestal 71 further to the radially inner side of the substrate W
than the first bracket 70. In the IPA nozzle moving mechanism 16, a
portion 16a fixed by the first bracket 70 overlaps with the first
guard raising/lowering mechanism 46 in plan view.
[0089] FIG. 4 is a block diagram for explaining an electrical
configuration of the main portion of the substrate processing
apparatus 1. The controller 3 includes a microcomputer, and
controls control objects provided in the substrate processing
apparatus 1 according to a prescribed control program. More
specifically, the controller 3 includes a processor (CPU) 3A and a
memory 3B in which the program is stored. The controller is
configured to execute various controls for substrate processing by
the processor 3A executing the program. In particular, the
controller 3 controls actions of the transfer robots IR and CR, the
IPA nozzle moving mechanism 16, the electric motor 23, the
shielding member raising/lowering mechanism 32, the shielding
member rotating mechanism 33, the guard raising/lowering mechanisms
46 to 48, the chemical liquid nozzle moving mechanism 52, and the
valves 51, 54, 56, 58, 60, 62, 68, etc.
[0090] FIG. 5 is a flowchart for explaining an example of substrate
processing performed by the substrate processing apparatus 1. The
figure mainly shows processing to be realized by the controller 3
executing the program. FIG. 6 is a time chart for explaining the
details of substrate processing.
[0091] In substrate processing by the substrate processing
apparatus 1, carry-in of a substrate (S1), chemical liquid
processing (S2), DIW rinse processing (S3), organic solvent
processing (S4), drying processing (S5), and carry-out of the
substrate (S6) are executed in this order as shown in FIG. 5, for
example.
[0092] First, in substrate processing by the substrate processing
apparatus 1, an unprocessed substrate W is carried from the carrier
C into the processing unit 2 and delivered to the spin chuck 5 by
the transfer robots IR and CR (S1). Then, the substrate W is held
horizontally by the spin chuck 5 until the substrate W is carried
out by the transfer robot CR (substrate holding step). The upper
surface of the substrate W horizontally held on the spin chuck 5
faces the facing surface 6a of the shielding member 6.
[0093] Next, the chemical liquid processing (S2) will be described.
After the transfer robot CR is retreated to the outside of the
processing unit 2, the chemical liquid processing (S2) in which the
upper surface of the substrate W is cleaned with the chemical
liquid is carried out.
[0094] Referring to FIG. 6, specifically, the controller 3 first
controls the IPA nozzle moving mechanism 16 to position the IPA
nozzle 13 at the retreat position. In addition, the controller 3
controls the shielding member raising/lowering mechanism 32 to
dispose the shielding member 6 at the higher position.
[0095] Then, the controller 3 drives the electric motor 23 to
rotate the spin base 21 at 800 rpm, for example. The substrate W
which is held horizontally thereby rotates at the same rotational
speed as the spin base 21 (800 rpm) (substrate rotating step).
Then, the controller 3 controls the shielding member rotating
mechanism 33 to rotate the shielding member 6. During this time,
the rotational direction of the shielding member 6 may be matched
with the rotational direction of the substrate W, and the
rotational speed of the shielding member 6 (the shielding member
rotational speed) and the rotational speed of the substrate W (the
substrate rotational speed) may be set to the same speed. In other
words, the shielding member 6 may be rotated in synchronization
with the spin base 21. The phrase "rotated in synchronization"
means rotations in the same direction at the same rotational
speed.
[0096] Then, the controller 3 controls the chemical liquid nozzle
moving mechanism 52 to dispose the chemical liquid nozzle 9 at a
chemical liquid processing position above the substrate W. The
chemical liquid processing position may be a position where the
chemical liquid discharged from the chemical liquid nozzle 9 is
landed on the rotation center of the upper surface of the substrate
W. The controller 3 opens the chemical liquid valve 54. Thereby,
the chemical liquid is supplied from the chemical liquid nozzle 9
toward the upper surface of the substrate W which is in a rotating
state. The supplied chemical liquid is spread over the entire upper
surface of the substrate W by centrifugal force. At this time, the
amount of the chemical liquid supplied from the chemical liquid
nozzle 9 (chemical liquid supply amount) is 2 liter/min, for
example.
[0097] The controller 3 controls the guard raising/lowering
mechanisms 46 to 48 to dispose the third guard 45 higher than the
substrate facing position. Consequently, the chemical liquid
splashed outside the substrate W by centrifugal force passes under
the third extension portion 45B of the third guard 45, and is
received by the third cylindrical portion 45A of the third guard
45. The chemical liquid received by the third cylindrical portion
45A flows to the first cup 41 (refer to FIG. 3).
[0098] Next, the DIW rinse processing (S3) will be described. After
chemical liquid processing (S2) for a fixed time period, the DIW
rinse processing (S3) is carried out. In the DIW rinse processing
(S3), the chemical liquid on the upper surface of the substrate W
is replaced with the DIW, thereby the chemical liquid from the
upper surface of the substrate W is removed.
[0099] Specifically, the controller 3 closes the chemical liquid
valve 54. The controller 3 controls the chemical liquid nozzle
moving mechanism 52 to retreat the chemical liquid nozzle 9 from
the upper side of the substrate W to the side of the spin base
21.
[0100] Then, the controller 3 opens the DIW valve 56. The
processing liquid such as DIW is thereby supplied from the
processing liquid supply unit such as the DIW nozzle 10 toward the
upper surface of the substrate W which is in a rotating state
(processing liquid supply step). The DIW is spread over the entire
upper surface of the substrate W by centrifugal force. The chemical
liquid on the substrate W is washed off by the DIW. At this time,
the amount of the DIW supplied from the DIW nozzle 10 (DIW supply
amount) is 2 liter/min, for example.
[0101] The controller 3 controls the shielding member
raising/lowering mechanism 32 to maintain a state with the
shielding member 6 positioned at the higher position. Then, the
controller 3 drives the electric motor 23 to keep the rotational
speed of the spin base 21 at 800 rpm, for example. The controller 3
controls the shielding member rotating mechanism 33 to keep the
rotational speed of the shielding member at 800 rpm, for
example.
[0102] The controller 3 controls the guard raising/lowering
mechanisms 46 to 48 to dispose the third guard 45 higher than the
substrate facing position. Consequently, the chemical liquid and
the DIW splashed outside the substrate W by centrifugal force
passes under the third extension portion 45B of the third guard 45,
and is received by the third cylindrical portion 45A of the third
guard 45. The chemical liquid and the DIW received by the third
cylindrical portion 45A flows to the first cup 41 (refer to FIG.
3).
[0103] In a state where the DIW is supplied from the DIW nozzle 10
toward the upper surface of the substrate W which is in a rotating
state, the controller 3 controls the shielding member
raising/lowering mechanism 32. The shielding member 6 is thereby
moved from the higher position to a first proximal position. When
the shielding member 6 is positioned at the first proximal
position, the facing surface 6a of the shielding member 6 is
proximal to the upper surface of the substrate W. When the
shielding member 6 is positioned at the first proximal position,
the distance between the upper surface of the substrate W and the
facing surface 6a is 7 mm, for example.
[0104] After the shielding member 6 has been disposed at the first
proximal position, the controller 3 may control the first guard
raising/lowering mechanism 46 to dispose the first guard 43 at the
shielding member facing position. The space A is thereby formed by
the substrate W, the shielding member 6, and the first guard 43
(space forming step).
[0105] Then, after the space A has been formed, the controller 3
opens the second inert gas valve 68, to supply inert gas from the
inert gas flow channel 18 toward the upper surface of the substrate
W. The flow rate of inert gas supplied from the inert gas flow
channel 18 (the inert gas flow rate) is 300 liter/min, for example.
The atmosphere in the space A is replaced by the inert gas supplied
from the inert gas flow channel 18 (inert gas replacement
step).
[0106] Then, after the space A has been formed, the controller 3
controls the electric motor 23 to rotate the spin base 21 at a
first processing liquid speed and maintain this state for a
prescribed time period. The substrate W is thereby rotated at the
first processing liquid speed when the DIW is supplied from the DIW
nozzle 10 onto the upper surface. The first processing liquid speed
is 1200 rpm, for example. Thereafter, rotation of the spin base 21
is accelerated to a second processing liquid speed, which is a
higher speed than the first processing liquid speed. Rotation of
the substrate W is thereby accelerated to the second processing
liquid speed (substrate accelerating step). The second processing
liquid speed is a speed at which the processing liquid such as DIW
on the substrate W can be rapidly spun off in the outward direction
from the substrate W. The second processing liquid speed is 2000
rpm, for example. Unlike the present preferred embodiment, the spin
base 21 may be rotated at the first processing liquid speed before
the space A is formed, or rotation of the spin base 21 may be
accelerated to the second processing liquid speed before the space
A is formed.
[0107] Also, after the space A has been formed, the controller 3
may control the second guard raising/lowering mechanism 47 to
dispose the second guard 44 at the substrate facing position. The
space A is thereby partitioned from the lower side by the second
extension portion 44B of the second guard 44. The controller 3 also
controls the third guard raising/lowering mechanism 48 to dispose
the third guard 45 lower than the substrate facing position.
[0108] The DIW that has splashed outside the substrate W by
centrifugal force passes between the first extension portion 43B of
the first guard 43 and the second extension portion 44B of the
second guard 44, and is received by the first cylindrical portion
43A of the first guard 43. Unlike the present preferred embodiment,
the DIW splashed outside the substrate by centrifugal force may be
received by the second cylindrical portion 44A of the second guard
44. In this case, the controller 3 controls the guard
raising/lowering mechanisms 46 to 48 to dispose the second guard 44
higher than the substrate facing position and dispose the third
guard 45 lower than the substrate facing position. The DIW received
by the second cylindrical portion 44A flows to the second cup 42
(refer to FIG. 3).
[0109] Net, the organic solvent processing (S4) will be described.
After DIW rinse processing (S3) for a fixed time period, organic
solvent processing (S4) is carried out. In the organic solvent
processing (S4), the DIW on the substrate W is replaced with an
organic solvent (for example, IPA) as a low surface tension liquid
with lower surface tension than the rinse liquid (for example,
water), to form an IPA liquid film, and thereafter the liquid film
is removed from the substrate W.
[0110] FIG. 7A to FIG. 7D are illustrative cross-sectional views of
the main part of the processing unit 2, for explaining the state of
organic solvent processing (S4 in FIG. 5).
[0111] In the organic solvent processing (S4), an organic solvent
rinsing step T1, a liquid film forming step T2, an opening forming
step T3, and a liquid film removing step T4 are carried out in that
order.
[0112] Referring to FIG. 6 and FIG. 7A, first, the organic solvent
rinsing step T1 is carried out in the organic solvent processing
(S4). In the organic solvent rinsing step T1, the DIW on the upper
surface of the substrate W is replaced with an organic solvent such
as IPA in state where the substrate W is being rotated.
[0113] The controller 3 closes the DIW valve 56. Thereby, supply of
the DIW from the DIW nozzle 10 is interrupted. The controller 3
opens the central IPA valve 58. Thereby, the IPA is supplied from
the central IPA nozzle 11 toward the upper surface of the substrate
W which is in a rotating state (center low surface tension liquid
supply step).
[0114] The controller 3 may control the shielding member
raising/lowering mechanism 32 to keep the shielding member 6
positioned at the first proximal position, and may control the
guard raising/lowering mechanisms 46 to 48 to keep the first guard
43 at the shielding member facing position. The state where the
space A is formed by the substrate W, the shielding member 6, and
the first guard 43 is thus maintained. When the second guard 44 is
positioned higher than the substrate facing position at the end of
the DIW rinse processing (S3), the controller 3 may control the
second guard raising/lowering mechanisms 47 to move the second
guard 44 to the substrate facing position.
[0115] The controller 3 controls the second inert gas valve 68, so
that the flow rate of the inert gas is 50 liter/min, for
example.
[0116] The controller 3 drives the electric motor 23 for high-speed
rotation of the spin base 21 at a first rotational speed. The
substrate W is thereby rotated at a high speed at the first
rotational speed. The first rotational speed is a speed at which
the processing liquid such as DIW can be spun off in the outward
direction from the substrate W. The first rotational speed is 2000
rpm, for example, and the first rotational speed may be the same
speed as the second processing liquid speed. That is, in the
organic solvent rinsing step T1, the substrate W is rotated at high
speed following the DIW rinse processing (S3). The IPA that has
been supplied spreads rapidly over the entire upper surface of the
substrate W by centrifugal force, and the DIW on the substrate W is
replaced by the IPA. In the organic solvent rinsing step T1, the
controller 3 may control the shielding member rotating mechanism
33, so that the shielding member rotational speed is 1000 rpm, for
example.
[0117] Referring to FIG. 6 and FIG. 7B, in the organic solvent
processing (S4), the liquid film forming step T2 is carried out
after completion of the organic solvent rinsing step T1. In the
liquid film forming step T2, a liquid film 110 of the IPA is formed
on the upper surface of the substrate W.
[0118] By continuing to supply IPA from the central IPA nozzle 11
to the upper surface of the substrate W, DIW on the substrate W is
replaced by IPA and the IPA liquid film 110 is formed on the upper
surface of the substrate W (liquid film forming step). The
controller 3 drives the electric motor 23 to decelerate rotation of
the spin base 21 to a second rotational speed. The second
rotational speed is lower than the first rotational speed. After
the DIW on the substrate W has been replaced with IPA and while the
liquid film forming step (rotation decelerating step) is
continuing, rotation of the substrate W is thereby decelerated to
the second rotational speed. The second rotational speed is 300
rpm, for example. The second rotational speed is a speed at which
the liquid film 110 can be held on the upper surface of the
substrate W after the liquid film 110 has been formed. The second
rotational speed is not limited to 300 rpm. The second rotational
speed may be any speed between 300 rpm to 500 rpm, for example, or
the second rotational speed may be a lower speed than 300 rpm (for
example, 50 rpm or lower).
[0119] After completion of the rotation decelerating step, the
controller 3 opens the heating fluid valve 51 to supply the heating
fluid from the lower surface nozzle 8 to the lower surface of the
substrate W. Heating of the substrate W is thereby initiated
(substrate heating step).
[0120] The controller 3 controls the shielding member rotating
mechanism 33 to keep the rotational speed of the shielding member
at 1000 rpm, for example. The controller 3 controls the shielding
member raising/lowering mechanism 32 to move (raise) the shielding
member 6 from the first proximal position to a second proximal
position, for example. In a case where the space A has been formed,
the interval between the upper surface of the substrate W and the
facing surface 6a of the shielding member 6 may be adjusted while
maintaining the space A (interval adjusting step). When the
shielding member 6 is positioned at the second proximal position,
the facing surface 6a of the shielding member 6 is proximal to the
upper surface of the substrate W. The second proximal position is a
position higher than the first proximal position. The position of
the facing surface 6a is higher when the shielding member 6 is
positioned at the second proximal position than when the shielding
member 6 is positioned at the first proximal position. When the
shielding member 6 is positioned at the second proximal position,
the distance between the facing surface 6a and the upper surface of
the substrate W is approximately 15 mm. The IPA nozzle 13 can move
in the horizontal direction between the facing surface 6a of the
shielding member 6 and the upper surface of the substrate W, when
the shielding member 6 is positioned at least at the second
proximal position or at a position higher than the second proximal
position.
[0121] In the interval adjustment step, the controller 3 controls
the first guard raising/lowering mechanism 46 to move the first
guard 43 together with the shielding member 6, with respect to the
substrate W. The first guard 43 is therefore disposed at the
shielding member facing position even after the interval adjusting
step. As a result, the state where the space A is formed is
maintained before and after the interval adjusting step. If the
second guard 44 is positioned higher than the substrate facing
position at the start of the liquid film forming step, then the
controller 3 may control the second guard raising/lowering
mechanism 47 to move the second guard 44 to the substrate facing
position.
[0122] While the liquid film 110 of the IPA is formed on the
substrate W, the controller 3 controls the IPA nozzle moving
mechanism 16 to move the IPA nozzle 13 disposed at the retreat
position toward the processing position. When the IPA nozzle 13 is
positioned at the processing position, the discharge port 13a of
the IPA nozzle 13 is shifted slightly (about 40 mm, for example)
from the center region of the substrate W toward the peripheral
edge side of the substrate W.
[0123] In the liquid film forming step T2, supply of inert gas from
the inert gas flow channel 18, that was initiated in the DIW rinse
processing (S3), is maintained. The flow rate of inert gas in the
liquid film forming step T2 is 50 liter/min, for example.
[0124] Referring to FIG. 6 and FIG. 7C, in the organic solvent
processing (S4), the opening forming step T3 is carried out after
completion of the liquid film forming step T2. In the opening
forming step T3, an opening 111 is formed in the center region of
the liquid film 110 of the IPA on the upper surface of the
substrate W. The center region of the liquid film 110 is the region
around the center of the liquid film 110. The center region of the
liquid film 110 includes the position of the liquid film 110 that
crosses with the rotational axis line C1.
[0125] In the opening forming step T3, first, the controller 3
controls the electric motor 23 to keep rotation of the spin base 21
at the second rotational speed.
[0126] Then, the controller 3 closes the central IPA valve 58 to
interrupt supply of the IPA to the upper surface of the substrate W
by the central IPA nozzle 11. The controller 3 then opens the IPA
valve 62 to initiate supply of the IPA from the IPA nozzle 13
toward the substrate W. A position in the upper surface of the
substrate W where the IPA is supplied from the IPA nozzle 13 is
referred to as a liquid landing point P. The landing point P is the
position in the upper surface of the substrate W where the IPA
supplied from the IPA nozzle 13 lands. The controller 3 then
controls the IPA nozzle moving mechanism 16 to move the IPA nozzle
13 disposed at the processing position toward the outer peripheral
position. When the IPA nozzle 13 is positioned at the outer
peripheral position, the discharge port 13a of the IPA nozzle 13
faces the peripheral edge of the substrate W (a position shifted by
140 mm, for example, from the center region of the substrate W
toward the peripheral edge side of the substrate W).
[0127] Then, the controller 3 controls the second inert gas valve
68 to blow the inert gas (for example, a N2 gas) perpendicularly
from the inert gas flow channel 18 toward the center region of the
upper surface of the substrate W (inert gas blowing step). The flow
rate of the inert gas at this time is 100 liter/min, for example. A
small opening 111 (for example, about 30 mm in diameter) is thereby
formed in the center region of the liquid film 110 on the substrate
W that is rotating at the second rotational speed, and the center
region of the upper surface of the substrate W is exposed (opening
forming step). The inert gas blowing step may be initiated
simultaneously with supply of the IPA from the IPA nozzle 13 that
is disposed at the processing position. The inert gas blowing step
may alternatively be initiated immediately after initiating supply
of the IPA from the IPA nozzle 13 that is disposed at the
processing position.
[0128] While the opening forming step is being carried out, the
controller 3 closes the heating fluid valve 51 to interrupt supply
of the heating fluid from the lower surface nozzle 8. Heating of
the substrate W is thereby interrupted while the opening forming
step is being carried out (heating interrupting step).
[0129] The controller 3 controls the shielding member rotating
mechanism 33 to keep the rotational speed of the shielding member
at 1000 rpm, for example. The controller 3 may control the guard
raising/lowering mechanisms 46 to 48 to move the guards 43 to 45
such that the state where the space A is formed is maintained. When
the second guard 44 is positioned higher than the substrate facing
position at the start of the opening forming step, the controller 3
may move the second guard 44 to the substrate facing position.
[0130] Referring to FIG. 6 and FIG. 7D, in the organic solvent
processing (S4), the liquid film removing step T4 is carried out
after completion of the opening forming step T3. In the liquid film
removing step T4, the liquid film 110 of the IPA on the upper
surface of the substrate W is removed.
[0131] In the liquid film removing step T4, after completion of the
opening forming step, the controller 3 opens the heating fluid
valve 51 to supply the heating fluid from the lower surface nozzle
8 to the lower surface of the substrate W. Heating of the substrate
W is thereby resumed (heating resuming step).
[0132] The controller 3 controls the electric motor 23 to keep
rotation of the spin base 21 at the second rotational speed. The
opening 111 is widened by centrifugal force of the substrate W that
is rotating at the second rotational speed, and the liquid film 110
of the IPA is gradually removed from the upper surface of the
substrate W (liquid film removing step).
[0133] When the opening 111 is widened, the controller 3 maintains
the open state of the IPA valve 62, and continues to supply the IPA
from the IPA nozzle 13 to a position of the upper surface of the
substrate W that is the outer side of the opening 111 (low surface
tension liquid supply step). The outer side of the opening 111 is
the opposite side to the rotational axis line C1 with respect to
the peripheral edge of the opening 111 (further toward the radially
outer side than the peripheral edge of the opening 111). The inner
side of the opening 111 is the rotational axis line C1 side with
respect to the peripheral edge of the opening 111 (further toward
the radially inner side than the peripheral edge of the opening
111).
[0134] The controller 3 moves the liquid landing point P so as to
follow widening of the opening 111 (liquid landing point moving
step). Specifically, the controller 3 controls the IPA nozzle
moving mechanism 16 to move the IPA nozzle 13 toward the peripheral
edge of the substrate W, in order to make the liquid landing point
P follow the widening of the opening 111. More specifically, the
driving mechanism 81 (refer to FIG. 3) rotationally drives the
support member 80 (refer to FIG. 3) around a prescribed central
axis. The IPA nozzle 13 thereby moves along the upper surface of
the substrate W toward the radially outer side (nozzle moving
step). The IPA nozzle moving mechanism 16 is an example of a liquid
landing point changing unit that changes the liquid landing point
P.
[0135] Blowing of the inert gas by the inert gas flow channel 18
may be continued until the liquid film 110 is removed from the
upper surface of the substrate W. Stated differently, blowing of
the inert gas by the inert gas flow channel 18 may be continued
until completion of the liquid film removing step. Action of the
blowing force of the inert gas onto the liquid film 110 of the IPA
promotes expansion of the opening 111. The flow rate of the inert
gas may be increased in a stepwise manner. For example, in the
present preferred embodiment, the inert gas flow rate is kept in a
state increased to 200 liter/min for a prescribed time period after
the opening 111 has been formed, and then kept in a state increased
to 300 liter/min for a prescribed time period thereafter.
[0136] At this time, the controller 3 may control the first inert
gas valve 60 to supply the inert gas also from the inert gas nozzle
12 to the center region of the upper surface of the substrate W.
Thereby, widening of the opening 111 is further promoted.
[0137] In the liquid film removing step T4, the controller 3
controls the shielding member rotating mechanism 33 to keep the
rotational speed of the shielding member at 1000 rpm, for example.
The controller 3 may control the shielding member raising/lowering
mechanism 32 to maintain a state with the shielding member 6
positioned at the second proximal position. The controller 3 may
control the guard raising/lowering mechanisms 46 to 48 to move the
guards 43 to 45 so that the state where the space A is formed is
maintained. In a case where the second guard 44 is positioned
higher than the substrate facing position at the start of the
liquid film removing step T4, the controller 3 may move the second
guard 44 to the substrate facing position.
[0138] In the opening forming step T3 and liquid film removing step
T4, the substrate W is rotated at a second rotational speed that is
a lower speed than the first rotational speed. Adhesion of the
heating fluid to the upper surface of the substrate W caused by
splashing of the heating fluid that has been supplied to the lower
surface of the substrate W is thus minimized. Adhesion of the IPA
droplets on the inner side of the opening 111 and on the facing
surface 6a of the shielding member 6, which is caused by splashing
of the IPA that has been supplied to a position of the upper
surface of the substrate W on the outer side of the opening 111, is
also minimized.
[0139] The liquid film removing step T4 is ended, for example, when
the IPA nozzle 13 reaches the outer peripheral position.
Alternatively, the organic solvent processing (S4) may be ended
when the peripheral edge of the opening 111 reaches the peripheral
edge of the substrate W.
[0140] Next, the drying processing (S5: spin drying) will be
described with reference to FIG. 6. After the organic solvent
processing (S4) is ended, the drying processing (S5) is carried
out. In the drying processing (S5), the liquid component on the
upper surface of the substrate W is spun off by centrifugal
force.
[0141] Specifically, the controller 3 closes the heating fluid
valve 51 to interrupt supply of the heating fluid to the lower
surface of the substrate W. The controller 3 controls the IPA
nozzle moving mechanism 16 to retreat the IPA nozzle 13 to the
retreat position. The controller 3 then controls the IPA valve 62
to interrupt supply of the IPA from the IPA nozzle 13. The
controller 3 then closes the first inert gas valve 60 to interrupt
supply of the inert gas from the inert gas nozzle 12.
[0142] Then, the controller 3 controls the shielding member
raising/lowering mechanism 32 to move the shielding member 6 to the
lower position. Then, the controller 3 controls the second guard
raising/lowering mechanisms 47 and the third guard raising/lowering
mechanisms 48 to dispose the second guard 44 and the third guard 45
lower than the substrate facing position. Then, the controller 3
controls the first guard raising/lowering mechanisms 46 to lower
the first guard 43 to dispose the first guard 43 at a position
slightly higher than the lower position and slightly higher than
the substrate facing position.
[0143] Then, the controller 3 controls the electric motor 23 to
accelerate the rotation of the spin base 21 in a stepwise manner.
Specifically, the rotation of the spin base 21 is maintained at 500
rpm, for example, for a prescribed time period, then accelerated to
750 rpm and maintained for a prescribed time period, and then
accelerated to 1500 rpm and maintained for a prescribed time
period. Thereby, the liquid component on the substrate W is spun
off by centrifugal force.
[0144] Then, the controller 3 controls the shielding member
rotating mechanism 33 to rotate the shielding member 6 at 1000 rpm,
for example. The controller 3 controls the shielding member
rotating mechanism 33 to accelerate the rotation of the shielding
member 6 to 1500 rpm at a timing when the rotational speed of the
substrate W becomes 1500 rpm, so that the spin base 21 and the
shielding member 6 are rotated in synchronization.
[0145] In the drying processing (S5), supply of the inert gas from
the inert gas flow channel 18 is maintained. The flow rate of the
inert gas is, for example, the same as the flow rate when the
liquid film removing step T4 is ended (300 liter/min). When the
rotation of the substrate W is accelerated to 1500 rpm, the
controller 3 controls the second inert gas valve 68 to reduce the
flow rate of the inert gas to 200 liter/min.
[0146] Thereafter, the controller 3 closes the second inert gas
valve 68 to interrupt supply of the inert gas from the inert gas
flow channel 18. The controller 3 controls the electric motor 23 to
interrupt the rotation of the spin chuck 5. The controller 3 then
controls the shielding member rotating mechanism 33 to stop
rotation of the shielding member 6. The controller 3 then controls
the shielding member raising/lowering mechanism 32 to retreat the
shielding member 6 to the higher position. Then, the controller 3
controls the guard raising/lowering mechanisms 46 to 48 to move the
guards 43 to 45 to the lower position.
[0147] Thereafter, the transfer robot CR enters the processing unit
2, scoops up the already-processed substrate W from the spin chuck
5, and carries the substrate W out of the processing unit 2 (S6).
The substrate W is delivered from the transfer robot CR to the
transfer robot IR, and housed in the carrier C by the transfer
robot IR.
[0148] According to the first preferred embodiment, in the liquid
film forming step, the IPA is supplied to the substrate W that is
rotating at the first rotational speed which is a relatively high
speed. After the DIW on the substrate W has been replaced with the
IPA, and while continuing the liquid film forming step, rotation of
the substrate W is decelerated to the second rotational speed that
is a lower speed than the first rotational speed. Consequently, the
centrifugal force acting on the DIW on the substrate W is great in
comparison to a substrate processing in which rotation of the
substrate W is accelerated in a stepwise manner during replacement
of DIW on the substrate W with the IPA. The time until replacement
of DIW on the substrate W with the IPA is therefore shortened.
Stated differently, the time until formation of the IPA liquid film
110 is shortened.
[0149] Incidentally, the centrifugal force acting on the IPA on the
substrate W that is rotating at the first rotational speed is as
great as the centrifugal force acting on the DIW on the substrate
W. However, when the DIW on the substrate W is replaced with the
IPA, the IPA continues to be supplied onto the upper surface of the
substrate W. Disruption of the liquid film 110 during formation can
therefore be minimized.
[0150] In addition, the time until replacement of the DIW on the
substrate W with the IPA can be shortened for the same reason, even
in comparison to a substrate processing in which the substrate W is
rotated at the second rotational speed that is a lower speed than
the first rotational speed, without changing the rotational speed
of the substrate W, during the liquid film forming step.
[0151] Furthermore, after completion of the liquid film forming
step, the opening 111 is formed in the center region of the liquid
film 110 in a state where the rotational speed of the substrate W
is kept at the second rotational speed. The centrifugal force
acting on the liquid film 110 is therefore lowered in comparison to
substrate processing in which rotation of the substrate W is
accelerated in the opening forming step or liquid film removing
step. Consequently, disruption of the liquid film 110 is minimized
and the liquid film 110 is satisfactorily removed from the upper
surface of the substrate W.
[0152] Thus, the time required for formation of the IPA liquid film
110 can be shortened and the liquid film 110 can be satisfactorily
removed.
[0153] Furthermore, the first rotational speed is a speed at which
the processing liquid such as DIW can be rapidly spun off outward
from the substrate. The DIW on the substrate W can therefore be
rapidly replaced by the IPA.
[0154] Furthermore, the second rotational speed is a speed at which
the liquid film 110 is held on the substrate W. Disruption of the
liquid film 110 can therefore be minimized.
[0155] The substrate W is rotated at the first processing liquid
speed while the DIW is supplied to the upper surface of the
substrate W, and thereafter rotation of the substrate W is
accelerated to the second processing liquid speed which is a higher
speed than the first processing liquid speed. Processing of the
upper surface of the substrate W by the DIW is therefore carried
out rapidly.
[0156] Also, since the second processing liquid speed is the same
speed as the first rotational speed, the DIW on the substrate W is
replaced with the IPA while keeping the rotational speed of the
substrate at a high speed. Therefore, the time required to change
the rotational speed of the substrate is reduced. Consequently, the
DIW on the substrate W can be rapidly replaced by the IPA.
[0157] Furthermore, the substrate W is heated in a state where the
liquid film 110 is held on the upper surface, and vaporization of
the IPA in the liquid film 110 is thereby accelerated. On the other
hand, while the opening forming step is being carried out, heating
of the substrate W is interrupted. Consequently, the opening 111 is
satisfactorily formed in the center region of the liquid film 110
and the IPA is moderately vaporized. Specifically, partial drying
of the center region of the liquid film 110 due to accelerated
vaporization of the IPA is minimized, when the opening 111 is
formed in the liquid film 110. Thus, residue of the IPA droplets on
the inner side of the opening 111 is minimized. The liquid film 110
on the substrate W is therefore rapidly removed by centrifugal
force of rotation of the substrate W, and vaporization of the IPA
by heating of the substrate W. The liquid film 110 on the upper
surface of the substrate W is satisfactorily removed as a
result.
[0158] Moreover, since heating of the substrate W is resumed after
completion of the opening forming step, vaporization of the IPA in
the liquid film 110 is accelerated even further after completion of
the opening forming step. The liquid film 110 on the upper surface
of the substrate W is even more satisfactorily removed as a
result.
[0159] Furthermore, the substrate heating step is initiated after
completion of the rotation decelerating step. That is, heating of
the substrate W is interrupted while the substrate W is being
rotated at a relatively high speed. Consequently, the liquid film
110 is rapidly formed, and exposure of the upper surface of the
substrate W due to disappearance of the IPA from the substrate W
before the opening forming step is minimized.
[0160] The opening forming step also includes an inert gas blowing
step of blowing an inert gas toward the center region of the liquid
film 110. Therefore, by blowing an inert gas, the opening 111 is
instantaneously formed in the center region of the liquid film 110
without leaving droplets in the center region of the substrate
W.
[0161] Also, the IPA is supplied to a position of the substrate W
further outward than the opening 111. Consequently, disruption of
the liquid film 110 caused by local vaporization of the IPA on the
outer side of the opening 111 is minimized.
[0162] Furthermore, by moving the position where the IPA is
supplied on the substrate W to follow widening of the opening 111,
the IPA continues to be supplied to a position further outward than
the opening 111, regardless of the size of the opening 111.
Consequently, disruption of the liquid film 110 caused by local
vaporization of the IPA on the outer side of the opening 111 is
further minimized.
Second Preferred Embodiment
[0163] Next, a second preferred embodiment of the present invention
will be described. FIG. 8 is an illustrative cross-sectional view
for explaining a configuration example of a processing unit 2Q in a
substrate processing apparatus 1Q according to the second preferred
embodiment. In the second preferred embodiment shown in FIG. 8, the
same members as those explained above are indicated by like
reference numerals, and their explanation will be omitted.
[0164] The main difference between the processing unit 2Q of the
second preferred embodiment shown in FIG. 8 and the processing unit
2 of the first preferred embodiment (refer to FIG. 3) is that a
shielding member 6Q of the processing unit 2Q includes a facing
member 91 and an annular portion 92. The facing member 91 faces the
upper surface of the substrate W. The annular portion 92 extends
downward from the peripheral edge portion of the facing member 91
so as to surround the substrate W in plan view.
[0165] The facing member 91 is formed to a disk shape. The facing
member 91 is disposed substantially horizontally above the spin
chuck 5. The facing member 91 has a facing surface 6a that faces
the upper surface of the substrate W. A hollow shaft 30 is fixed on
the side of the facing member 91 opposite the facing surface
6a.
[0166] The shielding member 6Q can be raised and lowered between a
higher position and a lower position by the shielding member
raising/lowering mechanism 32, similar to the shielding member 6 of
the first preferred embodiment, and The shielding member 6Q can be
positioned at the first proximal position and the second proximal
position between the higher position and the lower position. When
the shielding member 6Q is positioned at the lower position, the
first proximal position, or the second proximal position, the
annular portion 92 faces the substrate W from the horizontal
direction. When the annular portion 92 faces the substrate W from
the horizontal direction, the atmosphere between the facing surface
6a of the shielding member 6Q and the upper surface of the
substrate W is shielded from the ambient atmosphere.
[0167] In the shielding member 6Q, a penetrating hole 93
penetrating the annular portion 92 in the rotational radius
direction of the substrate W, is formed. The penetrating hole 93
penetrates the inner peripheral surface and the outer peripheral
surface of the annular portion 92. The inner peripheral surface of
the annular portion 92 of the shielding member 6Q is curved so as
to be lowered as the inner peripheral surface of the annular
portion 92 goes toward the radially outer side. The outer
peripheral surface of the annular portion 92 extends along the
vertical direction. The penetrating hole 93 has the form of a long
hole that is long in the vertical direction as viewed from the
radially outer side, for example.
[0168] Also, the processing unit 2Q does not include the cups 41,
42, guards 43 to 45, and the guard raising/lowering mechanisms 46
to 48 of the first preferred embodiment. The processing unit 2Q
instead includes a cup 94, a guard 95 and a guard raising/lowering
mechanism 96. The cup 94 surrounds the spin chuck 5. The guard 95
is formed integrally with the cup 94. The guard 95 receives the
processing liquid that has been removed out of the substrate W,
from the substrate W that is held by the spin chuck 5. The guard
raising/lowering mechanism 96 drives raising and lowering of the
guard 95.
[0169] Unlike the first preferred embodiment, the IPA nozzle 13 of
the second preferred embodiment extends in a linear manner in the
horizontal direction. Unlike the first preferred embodiment, the
discharge port 13a of the IPA nozzle 13 of the second preferred
embodiment extends downward from the tip of the IPA nozzle 13.
Also, the IPA nozzle moving mechanism 16 of the second preferred
embodiment is disposed further to the radially outer side than the
annular portion 92 of the shielding member 6Q. The IPA nozzle
moving mechanism 16 of the second preferred embodiment can move the
IPA nozzle 13 in a linear manner in the direction in which the IPA
nozzle 13 extends.
[0170] The IPA nozzle 13 can be inserted through the penetrating
hole 93. In a state where the penetrating hole 93 is positioned
higher than the substrate W (for example, in a state where the
shielding member 6Q is positioned at the second proximal position),
the IPA nozzle 13 can move between the position further toward the
rotational axis line C1 side than the annular portion 92 (further
toward the radially inner side than the annular portion 92), and a
position on the opposite side of the rotational axis line C1 with
respect to the annular portion 92 (further toward the radially
outer side than the annular portion 92), via the penetrating hole
93. That is, the penetrating hole 93 is provided in the annular
portion 92, and functions as a passage-allowing portion to allow
passage of the IPA nozzle 13 through the annular portion 92. In
FIG. 8, the IPA nozzle 13 that is disposed at a position further
toward the radially inner side than the annular portion 92 is
indicated by a two short dashed line.
[0171] In the substrate processing apparatus 1Q of the second
preferred embodiment, substantially the same substrate processing
can be carried out as with the substrate processing apparatus 1 of
the first preferred embodiment, except for the steps related to
raising and lowering of the guards 43 to 45 (refer to FIG. 3), and
therefore it will not be explained again. In substrate processing
with the substrate processing apparatus 1Q, however, it is
necessary to stop rotation of the shielding member 6Q when the IPA
nozzle 13 is passed through the penetrating hole 93 in the liquid
film forming step T2, the opening forming step T3, and the liquid
film removing step T4. Moreover, in substrate processing with the
substrate processing apparatus 1Q, the guard raising/lowering
mechanism 96 may be controlled to raise and lower the guard 95 such
that the guard 95 does not interfere with the IPA nozzle 13.
[0172] According to the second preferred embodiment, the same
effect as those of the first preferred embodiment are
exhibited.
Third Preferred Embodiment
[0173] Next, a third preferred embodiment of the present invention
will be described. FIG. 9 is an illustrative cross-sectional view
for explaining a configuration example of a processing unit 2R in a
substrate processing apparatus 1R according to the third preferred
embodiment of the present invention. In the third preferred
embodiment shown in FIG. 9, the same members as those explained
above are indicated by like reference numerals, and their
explanation will be omitted.
[0174] The main difference between the processing unit 2R of the
third preferred embodiment shown in FIG. 9 and the processing unit
2 of the first preferred embodiment (refer to FIG. 3) is that the
processing unit 2R includes a plurality of spaced IPA nozzles 100,
instead of the IPA nozzle 13.
[0175] The plurality of spaced IPA nozzles 100 are respectively
disposed at a plurality of positions at different distances from
the rotational axis line C1. The plurality of spaced IPA nozzles
100 supply the IPA toward a position distant from the rotation
center position of the upper surface of the substrate W. The
plurality of spaced IPA nozzles 100 are an example of low surface
tension liquid supply units that supply a low surface tension
liquid such as IPA to the upper surface of the substrate W. In this
preferred embodiment, the plurality of spaced IPA nozzles 100 are
disposed side by side along the rotational radius direction of the
substrate W. The tips (discharge ports) of each of the plurality of
spaced IPA nozzles 100 are housed respectively in a plurality of
supply ports 6c formed in the facing surface 6a of the shielding
member 6. The IPA discharged from the plurality of spaced IPA
nozzles 100 is supplied to the upper surface of the substrate W
through the supply ports 6c. In this preferred embodiment, the
plurality of supply ports 6c are penetrating holes running through
the shielding member 6 in the vertical direction Z.
[0176] A plurality of spaced IPA supply pipes 102 are respectively
coupled with the plurality of spaced IPA nozzles 100, and a
plurality of spaced IPA valves 103 are respectively interposed in
the plurality of spaced IPA supply pipes 102. Stated differently,
an individual spaced IPA supply pipe 102 is coupled with each
spaced IPA nozzle 100, and one spaced IPA valve 103 is interposed
in each spaced IPA supply pipe 102.
[0177] Each of the plurality of spaced IPA valves 103 constitutes a
supply switching unit that switches the IPA supply to the
corresponding spaced IPA nozzle 100 on or off. At least two spaced
IPA nozzles 100 are provided, and the IPA can be supplied from at
least two spaced IPA nozzles 100. The controller 3 can control the
plurality of spaced IPA valves 103 to change the liquid landing
point P to at least two positions other than the rotation center
position of the upper surface of the substrate W. In other words,
the plurality of spaced IPA valves 103 are an example of the liquid
landing point changing unit.
[0178] With the substrate processing apparatus 1R of the third
preferred embodiment, substantially the same substrate processing
can be carried out as with the substrate processing apparatus 1 of
the first preferred embodiment, except for the steps related to
raising and lowering of the guards 43 to 45 (refer to FIG. 3) and
rotation of the shielding member 6. However, the liquid film
removing step T4 of the organic solvent processing (S4)
differs.
[0179] The main difference between the organic solvent processing
(S4) with the substrate processing apparatus 1R of the third
preferred embodiment and the organic solvent processing (S4) with
the substrate processing apparatus 1 of the first preferred
embodiment is that in the liquid film removing step T4 with the
substrate processing apparatus 1R, the plurality of spaced IPA
nozzles 100 are used instead of the IPA nozzle 13.
[0180] In the liquid film removing step T4 with the substrate
processing apparatus 1R, the controller 3 sets the liquid landing
point P on the outer side of the opening 111 while the opening 111
is widened. The controller 3 then opens the spaced IPA valves 103
and initiates supply of a low surface tension liquid such as the
IPA from the corresponding spaced IPA nozzles 100 to the liquid
landing points P (low surface tension liquid supply step). The
controller 3 moves the liquid landing point P so as to follow
widening of the opening 111 (liquid landing point moving step).
[0181] Here, in FIG. 9, the reference numerals 100A to 100D are
used for denotation in order from the spaced IPA nozzle 100 nearest
the rotation center position of the substrate W. The reference
numerals 103A to 103D are used for denotation of the respective
spaced IPA valves 103 corresponding to the spaced IPA nozzles 100A
to 100D.
[0182] An example of the liquid landing point moving step according
to the third preferred embodiment will now be described in detail,
when a state in which the spaced IPA nozzle 100A is supplying the
IPA to the liquid landing point P immediately after the opening 111
has been formed (the state illustrated in FIG. 9), is assumed.
[0183] The controller 3 moves the liquid landing point P to the
radially outer side before the peripheral edge of the opening 111
reaches the liquid landing point P, in order to cause the liquid
landing point P to follow widening of the opening 111.
Specifically, before the peripheral edge of the opening 111 reaches
the position where the IPA supplied from the spaced IPA nozzle 100A
lands, the controller 3 closes the spaced IPA valve 103A and opens
the spaced IPA valve 103B. The spaced IPA nozzles 100 that supply
the IPA to the upper surface of the substrate W are thereby
switched from the spaced IPA nozzle 100A to the spaced IPA nozzle
100B. Then, before the peripheral edge of the opening 111 reaches
the position where IPA supplied from the spaced IPA nozzle 100B
lands, the controller 3 controls the spaced IPA valves 103. The
spaced IPA nozzles 100 that supply the IPA to the upper surface of
the substrate W are thereby switched to a different spaced IPA
nozzle 100 (spaced IPA nozzle 100C or spaced IPA nozzle 100D)
positioned on the radially outer side.
[0184] Thus, in the liquid film removing step T4 of the third
preferred embodiment, the spaced IPA nozzles 100 that supply the
IPA are switched to match widening of the opening 111, thereby the
liquid landing point P can be moved.
[0185] According to the third preferred embodiment, the same effect
as those of the first preferred embodiment are exhibited.
[0186] Moreover, according to the third preferred embodiment, it is
not necessary to move the nozzles between the shielding member 6
and the substrate W in the organic solvent processing (S4).
Consequently, the substrate W can thereby be processed with a state
where the shielding member 6 is close to the substrate W in
comparison to the first preferred embodiment.
[0187] Unlike the third preferred embodiment, a single spaced IPA
nozzle 100 may be provided in the processing unit 2R instead of the
plurality of spaced IPA nozzles 100.
[0188] The present invention is not restricted to the preferred
embodiments described above and may be implemented in yet other
modes.
[0189] For example, heating of the substrate W in the respective
preferred embodiments described above was carried out only by
supplying a heating fluid from the lower surface nozzle 8. However,
the substrate W may be heated using means other than the lower
surface nozzle 8. For example, a heater or the like built into
either or both the spin base 21 and the shielding member 6 may be
used for heating of the substrate W.
[0190] Also, in the respective preferred embodiments described
above, heating of the substrate W was not initiated in the organic
solvent rinsing step T1, but the substrate W may be heated in the
organic solvent rinsing step T1, unlike the first preferred
embodiment.
[0191] Also, the IPA nozzle 13 and the plurality of spaced IPA
nozzles 100 were configured such that the IPA was supplied onto the
upper surface of the substrate W. However, unlike the first
preferred embodiment to the third preferred embodiment, the IPA
nozzle 13 or the spaced IPA nozzles 100 may be configured so as to
supply a liquid other than the IPA. The liquid other than the IPA
may be a rinse liquid or chemical liquid, for example.
[0192] Furthermore, the discharge port 13a of the IPA nozzle 13 of
the first preferred embodiment and the second preferred embodiment
were configured such that the IPA was discharged in the vertical
direction (downward) onto the upper surface of the substrate W.
However, the discharge port 13a of the IPA nozzle 13 may be able to
discharge the IPA toward the upper surface of the substrate W in a
direction inclined with respect to the vertical direction and the
horizontal direction, unlike the first preferred embodiment and the
second preferred embodiment. The direction in which the IPA is
discharged from the discharge port 13a may be, for example, a
direction inclined with respect to the vertical direction and the
horizontal direction such that the direction is oriented toward the
peripheral edge side of the substrate W as the direction in which
the IPA is discharged from the discharge port 13a approaches the
upper surface of the substrate W.
[0193] In addition to the features described in the claims, the
following features can be extracted from the specification and the
attached drawings. These features can be arbitrarily combined with
the features described under SUMMARY OF THE INVENTION.
[0194] A1. A substrate processing method comprising:
[0195] a substrate holding step of holding a substrate
horizontally;
[0196] a processing liquid supply step of supplying a processing
liquid which contains a water to the horizontally held
substrate;
[0197] a substrate rotating step of rotating the horizontally held
substrate;
[0198] a liquid film forming step of supplying a low surface
tension liquid having a lower surface tension than water onto an
upper surface of the substrate, in order to replace the processing
liquid on the substrate with the low surface tension liquid and to
form a liquid film of the low surface tension liquid on the upper
surface of the substrate;
[0199] a substrate heating step of heating the substrate which is
horizontally held;
[0200] an opening forming step of forming an opening in a center
region of the liquid film on the substrate after completion of the
liquid film forming step; and
[0201] a liquid film removing step of widening the opening to
remove the liquid film from the upper surface of the substrate;
[0202] wherein the substrate heating step includes a heating
interrupting step of interrupting heating of the substrate which is
horizontally held, when the opening is formed.
[0203] For satisfactory formation of an opening in the liquid film
of the low surface tension liquid, it is necessary to prevent
residue of droplets of the low surface tension liquid on the inner
side of the opening. According to the substrate processing method
described in A1, heating of the substrate is interrupted when the
opening is formed in the center region of the liquid film of the
low surface tension liquid on the substrate. Therefore, since
vaporization of the low surface tension liquid due to heating of
the substrate is minimized when the opening is formed, local
vaporization of the low surface tension liquid in a portion of the
center region of the liquid film due to heating of the substrate is
also minimized. Consequently, residue of droplets of the low
surface tension liquid on the inner side of the opening is
minimized and an opening is thereby satisfactorily formed. As a
result, the liquid film is satisfactorily removed.
[0204] A2. The substrate processing method according to A1, wherein
the substrate heating step includes a step of resuming heating of
the substrate which is horizontally held, after completion of the
opening forming step.
[0205] According to the substrate processing method described in
A2, heating of the substrate is resumed after completion of the
opening forming step, and therefore vaporization of the low surface
tension liquid in the liquid film is accelerated after completion
of the opening forming step. Consequently, an opening is
satisfactorily formed and the liquid film is satisfactorily removed
from the upper surface of the substrate.
[0206] A3. The substrate processing method according to A1 or A2,
further including a rotation decelerating step of decelerating
rotation of the substrate while continuing the liquid film forming
step, after the processing liquid on the substrate which is
horizontally held has been replaced with a low surface tension
liquid having lower surface tension than water;
[0207] wherein the substrate heating step is initiated after
completion of the rotation decelerating step.
[0208] According to the substrate processing method described in
A3, in the rotation decelerating step, rotation of the substrate is
decelerated while continuing the liquid film forming step, after
the processing liquid on the substrate has been replaced with the
low surface tension liquid. Consequently, the time required until
the processing liquid on the substrate is replaced with the low
surface tension liquid is shortened, since the centrifugal force
acting on the processing liquid is great in comparison to a
substrate processing in which rotation of the substrate is
accelerated in a stepwise manner when the processing liquid on the
substrate is replaced with the low surface tension liquid.
[0209] Furthermore, the substrate heating step is initiated after
completion of the rotation decelerating step. That is, heating of
the substrate is interrupted while the substrate is being rotated
at a relatively high speed. Consequently, the liquid film is
rapidly formed, and exposure of the upper surface of the substrate
due to disappearance of the low surface tension liquid from the
substrate before the opening forming step is minimized.
[0210] A4. The substrate processing method according to A3, wherein
the rotation decelerating step includes a step of decelerating
rotation of the substrate from a first rotational speed at which
the processing liquid is spun off outward from the substrate which
is horizontally held, to a second rotational speed which is a lower
speed than the first rotational speed and at which the liquid film
to be held after the liquid film has been formed.
[0211] According to the substrate processing method described in
A4, the processing liquid on the substrate is satisfactorily
replaced by the low surface tension liquid, and disruption of the
liquid film is minimized.
[0212] While preferred embodiments of the present invention have
been described above, it is to be understood that variations and
modifications will be apparent to those skilled in the art without
departing the scope and spirit of the present invention. The scope
of the present invention, therefore, is to be determined solely by
the following claims.
[0213] The present application corresponds to Japanese Patent
Application No. 2016-168283 filed on Aug. 30, 2016 at the Japan
Patent Office, and the entire disclosure of this application is
incorporated herein by reference.
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